Mechanical seal cooler

ABSTRACT

A mechanical seal cooler having a solid body; a continuous first conduit within the body defining first conduit side walls; and a continuous second conduit disposed within the body defining second conduit side walls. The first conduit is spaced from and juxtaposed with the second conduit. A first fluid inlet port extends through the body and cooperates with an input end of the first conduit. A first fluid outlet port extends through the body, cooperating with an outlet end of the first conduit. A second fluid inlet port extends through the body, cooperating with an input end of the second conduit. A second fluid outlet port extends through the body cooperating with an outlet end of the second conduit. Concavities are through the first conduit and second side walls. A coupling attaches the solid body to a heat source device.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a mechanical seal cooler that will allow cooling the hot water around a mechanical seal in a high pressure, high temperature, hot water centrifugal pump.

2. Description of the Related Art

Centrifugal pumps are pumps that use a rotating impeller to increase the pressure of a fluid. The fluid enters the pump impeller along or near to the rotating axis and is accelerated by the impeller, flows radially outward into a diffuser or chamber of a volute, from where it exits an outlet, and into a downstream piping system. A centrifugal pump typically includes a rotating impeller that increases the velocity of the incoming fluid. A casing, or volute, of the pump then acts to convert this increased velocity into an increase in pressure, resulting in fluid flow. A centrifugal pump in its most basic configuration comprises a hollow casing shaped to contain a suction port and a discharge port, as well as one or more entry points through which a rotating shaft traverses the casing. An impeller is fastened to the shaft and is located approximately in the center of the casing. The shaft is supported by bearing brackets fastened to the outside of the casing. These brackets contain ball bearings that support the shaft and allow it to spin when coupled to an electric motor, and allow the impeller to perform the required pumping by taking the water coming from the suction port and pushing it centrifugally out of the discharged port. At the points where the shaft enters the casing, the water in the casing is contained and prevented from spilling out into the environment. Centrifugal pumps which operate at high temperatures, e.g., up to about and exceeding 400° F., typically incorporate features designed to protect the motor and seals from the high temperature of the working fluid in the pump housing.

The traditional way of accomplishing this task, has been to shape the entry points of the casing like a tube. The axis of this tube coincides with the axis of the rotating shaft. The space between the outside diameter of the shaft and the inside diameter of the tube, such as about ½″ to ¾″, would be filled with several rope packing rings so as to fill the cavity with pressure and reduce the leakage to a minimum. The tubular area where this rope packing is stuffed is commonly referred as a stuffing box. In the last 30 to 40 years there has been an increased intolerance for pumps fitted with rope packing and a way of accomplishing a seal at the entry points of the shaft into the casing, which is referred to as mechanical seal. In the simplest arrangement a mechanical seal has two components, a stationary annular component fitted into the stuffing box, and a rotating head which is spring loaded and fastened to the shaft. The stationary component is composed of a hard material such as silicon carbide and the rotating component is a softer, sacrificial material such as carbon. There would be an interface in a plane perpendicular to the shaft axis between the rotating carbon component and the stationary components.

The constant friction of the components generates heat which needs to be flushed with water at about 140° F. to 180° F. This need is even more prevalent when the water being pumped is already around 400° F. to 500° F.

Centrifugal pumps may also be air cooled. In this regard, U.S. Pat. No. 8,152,458 provides a tube heat exchanger in fluid communication with the seal housing interior reservoir. The heat exchanger is a coil type heat exchanger having inlet and outlet ends connected to the seal housing with the coil extending exterior to the seal housing. Lubricating fluid in the seal housing reservoir is directed into the inlet end of the heat exchanger, travels through and cools the coil, and then returns to the seal housing reservoir through the outlet end of the heat exchanger. The lubricating fluid is constantly recirculated and cooled through the seal housing reservoir, thus increasing the amount of heat carried away from the lubricating fluid which protects the mechanical seal from heat damage. The coil is adjacent a cooling fan located between the motor and seal housing. U.S. Pat. No. 8,092,154 provides an integrated fan plus a pump and heat exchanger housed in a cooling system. Air cooling is provided via an airflow created by the axial-flow fan, liquid cooling is provided via the centrifugal pump, and a heat transfer process is performed at the surface of drilled pump diffuser elements of the centrifugal pump where heat transfers from the relatively hot liquid to the air stream. U.S. Pat. No. 6,973,782 provides a pressurized hydraulic fluid system including a main pump and a charge pump provided for maintaining a sufficient inlet head pressure in the main pump. A heat exchanger and an electric motor driven cooling fan associated with the heat exchanger force cooling of hydraulic fluid flowing through the heat exchanger. U.S. Pat. No. 4,236,572 provides a fluid cooled heat exchanger system comprising a heat exchanger, first conduit means connected to the heat exchanger, a pump for pumping a cooling fluid to the heat exchanger via the first conduit means, second conduit means for receiving fluid from the pump that is in excess of the heat exchanger requirements. A valve is connected to the first and second conduit that fluid that has passed through. The heat exchanger via the first conduit means mixes in the valve with fluid that has by-passed the heat exchanger via the second conduit means, and the valve having a movable valve element which is moved off a valve seat by an amount dependent on the flow of fluid in the second conduit means. The flow of fluid through the heat exchanger is maintained substantially constant. By providing a substantially constant fluid flow through the heat exchanger, a substantial pressure drop across the heat exchanger at maximum fluid flow from the pump can be avoided. U.S. Pat. No. 4,069,906 discloses a cooling apparatus for drives having a housing containing a sump for a fluid which is heated by the generation of heat energy during operation of the drive. A centrifugal pump is driven by the input shaft and circulates fluid to a heat exchanger disposed about the outside surface of the housing. The cooled fluid is returned to a fluid sump which assures an ample supply of fluid at a relatively low pressure. A fan carried by an input shaft blows ambient air over the heat exchanger and exterior surface of the housing to enhance the level of heat dissipation.

The present invention provides an improved seal cooler which works by piping pump discharge water at around 400° F. into one side of the inventive cooler and piping water at around 50° F. to 65° F. on the other side of the seal cooler. The hot water enters the cooler in the center and exits on the outer port, while cold water enters the cooler in the outer port and exits at the center. This arrangement allows the two fluids to run counter each other and increases the heat exchange rate. Previous seal coolers had a tendency to clog and deteriorate prematurely due to the galvanic action between the different materials of construction such as copper and steel.

SUMMARY OF THE INVENTION

The invention provides a mechanical seal cooler which comprises a solid body; a continuous first conduit disposed within the body and defining first conduit side walls; a continuous second conduit disposed within the body and defining second conduit side walls;

the first conduit being spaced from and in juxtaposition with the second conduit;

a first fluid inlet port extending through the body cooperating with an input end of the first conduit, and a first fluid outlet port extending through the body cooperating with an outlet end of the first conduit;

a second fluid inlet port extending through the body cooperating with an input end of the second conduit and a second fluid outlet port extending through the body cooperating with an outlet end of the second conduit;

a plurality of concavities through the first conduit side walls and a plurality of concavities through the second conduit side walls; and

a coupling for attaching the solid body to a heat source device.

The invention also provides a method for cooling a heat source device which comprises

a) providing a heat source device, and

b) coupling the heat source device to a mechanical seal cooler;

the mechanical seal cooler comprising a solid body; a continuous first conduit disposed within the body and defining first conduit side walls; a continuous second conduit disposed within the body and defining second conduit side walls;

the first conduit being spaced from and in juxtaposition with the second conduit;

a first fluid inlet port extending through the body cooperating with an input end of the first conduit, and a first fluid outlet port extending through the body cooperating with an outlet end of the first conduit;

a second fluid inlet port extending through the body cooperating with an input end of the second conduit and a second fluid outlet port extending through the body cooperating with an outlet end of the second conduit;

a plurality of concavities through the first conduit side walls and a plurality of concavities through the second conduit side walls; and

a coupling for attaching the solid body to the heat source device;

c) passing a stream of a first fluid into the first fluid inlet port and the input end of the first conduit, through the outlet end of the first conduit and the first fluid outlet port;

d) passing a stream of a second fluid out of an exit end of a conduit of the heat source device into the second fluid inlet port and the input end of the second conduit, through the outlet end of the second conduit and the second fluid outlet port, and returning the second fluid to an input end of the conduit of the heat source device.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a mechanical seal cooler according to the invention.

FIG. 2 shows a view of one side of a central disk of a mechanical seal cooler showing a continuous first conduit disposed within the body on the cold water side of the central disk.

FIG. 3 shows a view of the reverse side of a central disk of a mechanical seal cooler showing a continuous second conduit disposed within the body on the hot fluid side of the central disk.

FIG. 4 shows a perspective view of the reverse side of a central disk of a mechanical seal cooler showing a continuous second conduit disposed within the body on the hot fluid water side of the central disk.

FIG. 5 shows a perspective view of a central disk of a mechanical seal cooler showing a continuous second conduit disposed within the body on the hot fluid side of the central disk, and having a plurality of concavities through its conduit walls.

DESCRIPTION OF THE INVENTION

FIG. 1 is a perspective view of a mechanical seal cooler 10 according to the invention. It comprises a solid body 12 optionally mounted on a pedestal 14. Preferably the solid body 12 comprises three metal disks, namely a cold side outer disk 16, a central disk 18, and a hot side outer disk 20. Disks 16, 18 and 20 are sandwiched together as shown and held together by a series of bolts through holes 22. The cold side outer disk 16 has a centrally located cold water inlet port 24 and a peripherally located cold water outlet port 26. Inlet port 24 leads to a cold water supply, such as a municipal water supply and outlet port 26 returns cold water which has been warmed to a higher temperature by extracting heat from the mechanical seal cooler. Hot side outer disk 20 is a mirror image of cold side outer disk 16 except it has a peripherally located hot fluid inlet, not shown, which receives a supply of hot fluid, such as hot water, from a centrifugal pump which is to be cooled, and a centrally located hot fluid outlet, not shown, which returns hot fluid to the centrifugal pump at a lower temperature than originally supplied.

FIG. 2 shows a view of a central disk 18 of the mechanical seal cooler showing the cold water side 28 of the central disk 18. It has a continuous first conduit 30, which is preferably spiral shaped, disposed within the body and defining first conduit side walls 32. Conduit 30 has a cold water inlet end 34 which is preferably positioned at about the center of the cold water side 28 of the central disk 18, and a cold water outlet end 36 which is preferably positioned at about the periphery of the cold water side 28 of the central disk 18.

FIG. 3 and FIG. 4 show a central disk 18 of the mechanical seal cooler showing the hot fluid side, such as hot water side, 38 of the central disk 18. It has a continuous second conduit 40, which is preferably spiral shaped, disposed within the body and defining second conduit side walls 42. Conduit 40 has a hot water inlet end 44 which is preferably positioned at about the periphery of the hot fluid side 38 of the central disk 18, and a hot water outlet end 46 which is preferably positioned at about the center of the hot fluid side 38 of the central disk 18. The first conduit 30 is spaced from and in juxtaposition with the second conduit 40. Preferably the first conduit 30 and the second conduit 40 are milled into opposite sides of central disk 18, but there is no connection between the first conduit 30 and the second conduit 40. As may be seen in FIG. 1, conduits 30 and 40 are sealed from leakage by sandwiching a smooth side of outer disk 16 and a smooth side of outer disk 20 onto opposite side of central disk 18, and all three disks are bolted together. Cold water inlet port 24 of cold side outer disk 16 cooperates with cold water inlet end 34 at about the center of the cold water side 28 of the central disk 18. Cold water outlet port 26 of cold side outer disk 16, cooperates with cold water outlet end 36 at about the periphery of the cold water side 28 of the central disk 18. A hot water inlet port of hot side outer disk 20 cooperates with hot water inlet end 44 at about the periphery of the hot water side 38 of the central disk 18. A hot water outlet port of hot side outer disk 20, cooperates with hot water outlet end 46 at about the center of the hot water side 38 of the central disk 18.

FIG. 5 shows a perspective view of central disk 18 of a mechanical seal cooler showing a continuous second conduit 40 disposed within the body on the hot fluid side of the central disk, and having a plurality of concavities 48 through its conduit walls 42. Corresponding concavities are disposed through the walls 32 of conduit 30 on the cold water side of central disk 18. These concavities through the walls 32 and 42 of conduits 30 and 40 are an important feature of the invention since they increase the effective surface areas of walls 32 and 42 which contact the hot and cold fluids which flow in conduits 30 and 40, thus increasing heat exchange and cooling from the hot fluid to the cold water. In another embodiment, the concavities have a roughened surface obtained by a suitable roughening treatment which further increases the surface area of the concavities contacting the fluids.

A suitable coupling, such as threaded piping, attaches the solid body to a heat source device, which is preferably a centrifugal pump. Another suitable coupling, such as threaded piping, attaches the solid body to a water supply source. Thus a hot water outlet conduit from a centrifugal pump is coupled to an inlet port of hot side outer disk 20 which cooperates with hot water inlet end 44 of central disk 18. A hot water inlet conduit from a centrifugal pump is coupled to an outlet port of hot side outer disk 20 which cooperates with hot water outlet end 46. Another suitable coupling comprises a plurality of bolts coupling the solid body to a heat source device.

Cold water outlet from a municipal supply is coupled to an inlet port of 24 of cold side outer disk 16 which cooperates with cold water inlet end 34 of central disk 18. A cold water conduit back to a municipal supply is coupled to an outlet port of cold side outer disk 16 which cooperates with cold water outlet end 36.

In use, one passes a stream of a first fluid, such as water, into the first fluid inlet port 24 and the input end 34 of the first conduit 30, and passes the now heated water through the outlet end 36 of the first conduit 30 and the first fluid outlet port 26 back to a water supply source or to a drain. One passes a stream of a hot second fluid out of an exit end of a conduit of the heat source device into the second fluid inlet port and the input end 44 of the second conduit 40, through the outlet end 46 of the second conduit 40 and the second fluid outlet port, and returning the now cooled second fluid to an input end of the conduit of the heat source device.

In one embodiment of the invention, the first conduit 30 and the second conduit 40 are spiral shaped. In another embodiment the first conduit 30 and the second conduit 40 are spiral shaped and they are concentrically aligned, such as on opposite sides of central disk 18. Alternately, conduits 30 and 40 may be milled completely through central disk 18 such that they are juxtaposed with one another in an interdigitated fashion such that their fluids do not intermix. In one embodiment the heat source device is a pump, such as a mechanical pump, however, it can also be any other device containing a flow of hot fluid which must be cooled. The solid body members may be composed of any suitable materials, such as metals, in particular, stainless steel, copper, aluminum or combinations thereof. Further embodiments of the invention dispose a suitable thermometer at one or both of the first fluid outlet port and the second fluid outlet ports. Further embodiments of the dispose a pressure gauge at one or both of the first fluid outlet port and the second fluid outlet ports.

In a typical operation, the stream of the first fluid passing into the first fluid inlet port has a pressure of from about 50 psi to about 75 psi and a temperature of from about 55° F. to about 80° F., preferably from about 55° F. to about 65° F., and the stream of the first fluid passing out of the first fluid outlet port has a pressure of from about 50 psi to about 75 psi and a temperature of from about 150° F. to about 200° F.

In a typical operation, the stream of the second fluid out of an exit end of the conduit of the heat source device into the second fluid inlet port has a pressure of from about 300 psi to about 500 psi and a temperature of from about 350° F. to about 500° F. and the stream of the second fluid passing through the outlet end of the second conduit and the second fluid outlet port and returning the second fluid to an input end of the conduit of the heat source device has a pressure of from about 300 psi to about 500 psi and a temperature of from about 100° F. to about 160° F., preferably from about 120° F. to about 140° F.

While the present invention has been particularly shown and described with reference to preferred embodiments, it will be readily appreciated by those of ordinary skill in the art that various changes and modifications may be made without departing from the spirit and scope of the invention. It is intended that the claims be interpreted to cover the disclosed embodiment, those alternatives which have been discussed above and all equivalents thereto. 

What is claimed is:
 1. A mechanical seal cooler which comprises a solid body; a continuous first conduit disposed within the body and defining first conduit side walls; a continuous second conduit disposed within the body and defining second conduit side walls; the first conduit being spaced from and in juxtaposition with the second conduit; a first fluid inlet port extending through the body cooperating with an input end of the first conduit, and a first fluid outlet port extending through the body cooperating with an outlet end of the first conduit; a second fluid inlet port extending through the body cooperating with an input end of the second conduit and a second fluid outlet port extending through the body cooperating with an outlet end of the second conduit; a plurality of concavities through the first conduit side walls and a plurality of concavities through the second conduit side walls; and a coupling for attaching the solid body to a heat source device.
 2. The mechanical seal cooler of claim 1 wherein the first conduit and the second conduit are spiral shaped.
 3. The mechanical seal cooler of claim 1 wherein the first conduit and the second conduit are spiral shaped and are concentrically aligned.
 4. The mechanical seal cooler of claim 1 wherein the heat source device is a pump.
 5. The mechanical seal cooler of claim 1 wherein the solid body comprises stainless steel, copper, aluminum or combinations thereof.
 6. The mechanical seal cooler of claim 1 wherein the coupling comprises a plurality of bolts.
 7. The mechanical seal cooler of claim 1 wherein the side walls and the concavities have a roughened surface.
 8. The mechanical seal cooler of claim 1 further comprising a thermometer disposed at least one of the first fluid outlet port and the second fluid outlet port.
 9. The mechanical seal cooler of claim 1 further comprising a pressure gauge disposed at least one of the first fluid outlet port and the second fluid outlet port.
 10. The mechanical seal cooler of claim 1 further comprising a pedestal and the solid body is mounted on the pedestal.
 11. A method for cooling a heat source device which comprises a) providing a heat source device, and b) coupling the heat source device to a mechanical seal cooler; the mechanical seal cooler comprising a solid body; a continuous first conduit disposed within the body and defining first conduit side walls; a continuous second conduit disposed within the body and defining second conduit side walls; the first conduit being spaced from and in juxtaposition with the second conduit; a first fluid inlet port extending through the body cooperating with an input end of the first conduit, and a first fluid outlet port extending through the body cooperating with an outlet end of the first conduit; a second fluid inlet port extending through the body cooperating with an input end of the second conduit and a second fluid outlet port extending through the body cooperating with an outlet end of the second conduit; a plurality of concavities through the first conduit side walls and a plurality of concavities through the second conduit side walls; and a coupling for attaching the solid body to the heat source device; c) passing a stream of a first fluid into the first fluid inlet port and the input end of the first conduit, through the outlet end of the first conduit and the first fluid outlet port; d) passing a stream of a second fluid out of an exit end of a conduit of the heat source device into the second fluid inlet port and the input end of the second conduit, through the outlet end of the second conduit and the second fluid outlet port, and returning the second fluid to an input end of the conduit of the heat source device.
 12. The method of claim 11 wherein the first conduit and the second conduit are spiral shaped and are concentrically aligned.
 13. The method of claim 11 wherein the heat source device is a pump.
 14. The method of claim 11 wherein the solid body comprises stainless steel, copper, aluminum or combinations thereof.
 15. The method of claim 11 wherein the coupling comprises a plurality of bolts.
 16. The method of claim 11 wherein the side walls and the concavities have a roughened surface.
 17. The method of claim 11 further comprising a thermometer disposed at least one of the first fluid outlet port and the second fluid outlet port.
 18. The method of claim 11 further comprising a pressure gauge disposed at least one of the first fluid outlet port and the second fluid outlet port.
 19. The method of claim 11 wherein the stream of the first fluid passing into the first fluid inlet port has a pressure of from about 50 psi to about 75 psi and a temperature of from about 55° F. to about 80° F. and wherein the stream of the first fluid passing out of the first fluid outlet port has a pressure of from about 50 psi to about 75 psi and a temperature of from about 150° F. to about 200° F.
 20. The method of claim 11 wherein the stream of the second fluid out of an exit end of the conduit of the heat source device into the second fluid inlet port has a pressure of from about 300 psi to about 500 psi and a temperature of from about 350° F. to about 500° F. and the stream of the second fluid passing through the outlet end of the second conduit and the second fluid outlet port and returning the second fluid to an input end of the conduit of the heat source device has a pressure of from about 300 psi to about 500 psi and a temperature of from about 100° F. to about 160° F. 